a$.$ Using computer software, compare $2019$ sales to $2020$ sales for each brand by computing the difference. Make a list of the brands that increased sales in $2020$ compared to $2019$; make a list of brands that decreased sales.

$\backslash$table$[[$Brand$,],[$Tesla$,],[$Volvo$,],[$Mazda$,],[$Alfa Romeo,$],[$Porsche$,],[$Genesis$,],[$Fiat$,],[$Lincoln$,],[$Volkswagen$,],[$Mini$,],[$Jaguar$,],[$Land Rover,$],[$Chrysler$,],[$Acura$,],[$Lexus$,],[$Cadillac$,],[$Mercedes$-$Benz,$],[$Kia$,],[$Mitsubishi$,]]$